COMMERCE CITY — When the summer transfer window opens Monday, the Colorado Rapids won’t have to look far to bolster their back line.

Defender Joseph Greenspan, the Rapids’ 2015 second-round SuperDraft pick (No. 26 overall) who left the club this offseason due to his Naval commitment, has rejoined the Rapids and a roster move appears imminent.

“Joe’s training with us. The Navy has released him,” Paul Bravo, the Rapids VP of soccer operations and technical director, said Tuesday. “So right now, it’s getting him soccer-specific training. We may look to loan him to get a couple of games under his belt, but we expect him to be ready to go within the next two weeks.”

Lt. Cmdr. Nathan Christensen, a spokesman for the U.S. Navy, said Ensign Greenspan served one year on active duty as a surface warfare officer then applied to be released early from his active duty Naval commitment.

Assistant Secretary of Defense Todd A. Weiler approved the waiver “to facilitate participation in a professional sports activity,” and Greenspan was permitted to join the Navy Reserve. He can be recalled to active duty.

“They basically do their day jobs and then they’ll serve in the military ‘X’ number of days a year,” Christensen said.

Christensen said Greenspan would serve part time and take part in occasional drills.

Provided by the U.S. Naval Academy

Defender Joseph Greenspan, seen here in a 2015 file photo, is back training with the Rapids after being released by the Navy.

Bravo said the Rapids can’t officially add him to the roster until Monday at the earliest when the transfer window opens.

The 6-foot-6 defender appeared in three league games for Colorado last season. He also started two U.S. Open Cup matches and scored a goal.

The Rapids defense has been the best in MLS this season, having allowed a league-low 11 goals through 16 games, but the depth has been tested of late after center backs Sean St. Ledger and Bobby Burling both underwent arthroscopic knee surgery.

With the impending addition of Greenspan, Bravo said the club is not likely to search for center back depth during the summer transfer window.

The Colorado Rapids were one defensive stop away from a hard-fought road point in head coach Anthony Hudson's MLS debut on Saturday. But then Chris Tierney snatched all three points for New England, scoring a free kick in the 93rd minute at Gillette Stadium to push the Revolution to a 2-1 win.

With a new head coach and an abundance of new faces, the Colorado Rapids open their 23rd MLS season Saturday at New England. Anthony Hudson, a Seattle native whose father Alan played for Arsenal and the Seattle Sounders of the old North American Soccer League, promises to bring a "positive and aggressive" style of soccer featuring dual strikers and a...